Releasable coupling for use in well bores



March 10; 1970 MFR-CONRAD RELEASABLE COUPLING. FOR USE IN WELL BORES Ori inali'iled Aug. 17, 19s? 2 Sheets- Sheet 1 Mar/f; .5. ("an/ad INVENTOR'.

March 10, 1970 M. B. CONRAD 4 5 RELEASABLE COUPLING FOR USE IN WELL BORES I Original Filed Aug. 17, 1967. 2 Sheets-Sheet 2 Mar/#2 15. Con/0a INVENTOR.

BY x/Mz/m/ ATTORA EV United States Patent 3,499,665 RELEASABLE COUPLING FOR USE IN WELL BORES Martin B. Conrad, Carpinteria, Calif., assignor to Schlumberger Technology Corporation, Houston, Tex., a corporation of Texas Original application Aug. 17, 1967, Ser. No. 661,422, now

Patent No. 3,422,898, dated Jan. 21, 1969. Divided and I this application Aug. 12, 1968, Ser. No. 763,473

Int. Cl. F161 37/08, 39/04 U.S. Cl. 2853 4 Claims ABSTRACT OF THE DISCLOSURE This is a division of application Ser. No. 661,422, filed Aug. 17, 1967 now Patent No. 3,422,898.

BACKGROUND OF THE INVENTION The present invention relates generally to well equipment and more particularly to new and improved apparatus for setting well tools in well bores.

Prior setting tools for use in setting well tools such as bridge plugs, packers, or the like, have utilized mechanisms which apply oppositely directed forces to such well tools. Such forces are usually generated by applying tension to a tubing string, rotating the tubing string, or initiating an explosive charge within the setting tool. The most comon problems with any such devices are the positive setting of the well tool and a positive release of the setting tool from the well tool after setting has been accomplished. In addition, the setting of a well tool by tension applied to a tubing string incurs the factor of tubing strength which may permit only a limited tension to be applied to the tubing string. Moreover, many prior setting tools have not been provided with a central passage which is large enough to permit the running of perforation guns or the like without first withdrawing such setting tools from the well.

SUMMARY OF THE INVENTION It is the primary objective of the present invention to provide a new and improved setting tool which overcomes the problems set forth above, and which enables positive setting of well tools in well bores. Another objective of this invention is the provision of a new and improved setting apparatus including a coupling mechanism which enables positive release of the setting apparatus from the well tool after the tool is set, such coupling mechanism being remotely operated in a convenient manner. Yet another objective is the provision of a new and improved mechanical setting tool apparatus which can be used to apply high setting loads to a well tool without the danger of exceeding the allowable strain strength of the runningin string. Still another objective of the present invention is to provide a new and improved mechanical type setting tool which is conveniently arranged to have aful opening bore therethrough for the passage of other well instruments into the well bore without having to first remove the setting tool from the well.

3,499,665 Patented Mar. 10, 1970 The present invention as embodied in a mechanical setting tool is claimed in the aforementioned parent application, now US. Patent No. 3,422,898. A releasable coupling apparatus in accordance with the present invention connects an inner member within an outer member, and includes an expansible and contractible latch member contracted around the inner member. A support is coupled to both the outer member and the latch means and functions to retain the latch in contracted condition. However, in response to a predetermined magnitude of force on the outer member, the support is uncoupled and permitted to move into a recess in the outer member where a holding means retains the support member. The outer member can then be moved downwardly to then upwardly to release the latch means from the inner member. Thus it will be apparent that a coupling apparatus is provided that can be conveniently operated from a remote point by simple longitudinal movement of one member.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention both as to its structural organization and manner of operation, together with further advantages thereof, may best be understood by way of illustration and example of preferred embodiments when taken in conjunction with accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 illustrates, in partial longitudinal cross section, details of the setting tool, embodying principles of the present invention, and a well tool connected thereto;

FIGURE 2 is a more detailed view, in partial longitudinal cross section, of a lower portion of the setting tool and release mechanism in a running-in condition;

FIGURE 3 is an enlarged fragmentary View, in longitudinal section, of the lower portion of the setting tool and release mechanism as the well tool is being set; and,

FIGURE 4 is a view similar to FIGURE 3 of the lower portion of the setting tool and release mechanism after release from the well tool and during a secondary setting operation.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring initially to FIGURE 1, a setting apparatus generally indicated by the reference numeral 13 is suspended in a well bore on a running-in string'14 of tubing or drill pipe and is shown releasably coupled at its lower end to a well tool 15 such as a bridge plug or the like. The tool 15 includes an elongated cylindrical mandrel or body 16 which can have a blind bore 21 and an enlarged guide member 17 at its lower end which supports lower slips 26. A lower expander cone 28 is arranged to shift the lower slips 26 outwardly and an elastomericpacking element 32 surrounds the mandrel 16 between the lower expander cone and an upper expander cone 33. Upper slips 34 are arranged about the mandrel 16 and have inner inclined surfaces 36 which can engage'the upper expander cone 33 in a manner whereby the cone can shift the upper slips outwardly. In like manner, the lower slips 26 have inner inclined surfaces 27 which engage companion outer surfaces 29 on the lower expander cone 28. The upper and lower slips 34 and 26 have wickers or teeth on their outer peripheries which are respectively formed to face upwardly and downwardly and which are respectively adapted to anchor against upward and downward movement when shifted outwardly into gripping engagement with the surrounding wall surface of easing P.

A setting head 38 is slidably mounted around the upper end portion of the mandrel 16 and is arranged to engage the upper slip members 34 as the mandrel moves'upward- 1y therethrough. As shown more clearly in FIGURE 2, the head 38 has an internal annular recess 39 which coritains a conventional ratchet lock ring 40. The lock ring 40 can be radially split so as to be expansible and contractible and has outer upwardly facing ratchet teeth 41 which are cooperable with downwardly facing companion teeth 42 within the recess in the setting head 38. Moreover, the ring 40 has inner upwardly facing teeth 43 which can engage companion downwardly facing teeth 44 on the mandrel 16. The ring 4t) has sufiicient lateral play between the setting head 38 and the mandrel 16 to ratchet downwardly over the mandrel 16 but cannot move upwardly on the mandrel. Accordingly, the ring 40 can function to lock the slips 34 and 26 in expanded condition as well as to trap compression loading in the packing element 32 when the well tool 15 is set. The mandrel 16 is coupled by means of a selectively operable release mechanism 45 to the setting tool in accordance with principles of the present invention. This release mechanism will be described in greater detail below with reference to FIGURES 2, 3 and 4.

The setting tool 13 is comprised of a central operating mandrel 46 which is connected at its upper end to the pipe string 14 for lowering the apparatus into the well bore. The central opening 47 of the mandrel 46 is sized to continue the full bore size of the string 14. The setting tool further includes an upper drag block and slip assembly 48 which is slidably mounted about the upper end of operating mandrel 46. A I-slot 49 and J-pin 50 are utilized to control relative movement between the assembly 48 and the mandrel 46. Below the assembly 48 is an expander come 51 which is mounted on a support sleeve 52 which is, in turn, threadedly connected to a setting sleeve 53 extending downwardly into engagement with the setting head 38. The expander cone 51 moves with the mandrel 46 to activate slips 53 on the assembly 48 whereupon the cone is slidable relative to the mandrel 46 to apply the holding force of the slips 53 to the setting head 38 via the support sleeve 52 and the setting sleeve 53. Suitable openings 54 in the setting sleeve and ports 55 in the mandrel can provide for fluid communication between the interior of the mandrel and the exterior of the tool string.

The assembly 48 includes a tubular cage 56 slidably received on the mandrel 46. A stop collar 57 can be appropriately connected to the mandrel 46 to limit upward movement of the cage. The cage has a plurality of circumferentially-spaced, longitudinally-extending recesses 58, each of which receives a typical friction drag block 59. Between each drag block and the cage is a coil spring 60 to urge the drag blocks radially outwardly into frictional engagement with the casing P. Each drag block also has end portions or flanges 61 (only one end shown) to limit outward movement of the blocks relative to the cage 56.

Operatively associated with each drag block 59 is a slip element 53 which has a head 63 and a stem 64. To accommodate a respective slip element, each drag block 59 can have a slot in which a stem-is received. Pins 66 pivotally connect respective stems of each slip element to the drag blocks 59. Each slip head 63 has external wickers or teeth which are formed to face upwardly, and an inner inclined surface 67 which is companion in shape to external inclined surfaces 74 on the expander cone 51. Spring 69 are inserted into each recess 57 to urge tangs 68 on the ends of each stem outwardly. Thus, the slip heads 63 are pivoted inwardly toward the mandrel 46 when the various parts of the setting mechanism 13 are in relative positions for longitudinal shifting in the well bore.

The J-pin and slot arrangement is conventional and is described fully in application Ser. No. 419,742 by Maurice P. Lebourg, filed Dec. 21, 1964 and now Patent No. 3,352,362. When the various parts of the assembly 48 are in the relative positions shown in FIGURES l and 2, that is, in positions for being run into a well, the lug 50 is disposed at a point in the upper end of a short vertical- 1y extending portion (not shown) of the J-slot 49. Th

resistance caused by frictional engagement of the drag blocks 59 with the casing P allows the setting tool mandrel 46 to be manipulated relative to the assembly 48 by the pipe string 14. A transverse portion of the J-slot connects the short vertical portion of the slot to permit movement of the lug to a long vertical portion of the slot by rotation of the mandrel accompanied with vertical movement of the mandrel. When the lug is disposed in the long vertical portion of the J-slot 49, the mandrel 46 can be elevated relative to the assembly 48 to bring the expander cone 51 within the slip elements 53 to shift them out- 'wardly into gripping engagement with the casing P. When the slips 53 thus grip the casing, the setting sleeve 53, seating head 38 and upper well tool slips 34 cannot move any further upwardly, and this coaction of parts permits setting the well tool 15 as will be more fully described hereafter.

Below the J-slot 49 in the mandrel 46 is a downwardly facing shoulder or stop 71. Spaced downwardly from this shoulder 71 is a rectangularly shaped split ring 72 which is received in an appropriate groove in the mandrel 46. Slidably mounted on the mandrel 46 between stop 71 and ring member 72 is an annular support ring 73. The support ring 73 is co-extensive with and supports the expander cone 51 in its expanded condition. As further described in detail in the aforementioned application Ser. No. 419,742, the cone 51 can have sets of alternating longitudinal slots 76 cut therein to render the core readily expansible and contractible. The support ring 73 can have stepped portions which engage complimentarily stepped portions within the bore of the expander cone 51. Hence, when the ring 73 is inserted in the cone 51, the cone is expanded radially outwardly. However, when the support ring 73 is moved sufiiciently upwardly relative to the expander cone 51, the ring no longer supports the cone and permits it to move radially inwardly to contracted condition whereupon the outward force on the slips 53 is released and the slips can release from gripping engagement with the well casing P.

The selectively releasable connecting mechanism 45 in accordance with the present invention is shown in greater detail in FIGURE 2. An annular recess 81 is formed in the lower end portion of the mandrel 46. An annular groove 83 is provided at the lower end of the recess 81 to form an enlargement of the recess. A support ring 84 is initially located in an upper position within the recess and is releasably retained in its upper position by one or more shear pins 86 which can extend through the mandrel wall and into the ring. The support ring 84 has a radially cut slot (not shown) through its wall to enable the ring to occupy a contracted diameter as shown in FIGURE 2. In this condition, an outwardly extending lock flange 87 at its lower end of the ring engages the wall of the recess 81 above the groove 83. Also, the ring 84 is provided with an internal annular notch 88 around its upper end portion. A companion notch 89 can be formed at the upper end of the recess 81 so that the notches together form an internal annular groove.

An external annular groove 92 is formed in the Well tool mandrel 16 near its upper end. A split lock ring 91 is arranged to engage within the groove 92 and within the groove provided by the support ring and mandrel notches 88 and 89. The ring 91 is also initially contracted within the groove 92 and is retained therein by the inwardly facing annular surfaces 93 and 94 (FIGURE 3) of the respective support ring and mandrel notches 88 and 89. With the lock ring 91 thus engaged as shown in FIGURE 2, the well tool mandrel 16 and the setting tool mandrel 46 are quite rigidly coupled to one another so that the well tool can be lowered to setting depth. However, when a predetermined magnitude of upwardly directed setting force is applied, the shear pin 86 will rupture. When this occurs, the support ring 84 will move to a lower position within the recess 81 until the lock flange 87 is adjacent to the recess groove 83, whereupon the support ring 84 wi l resile outwardly and the flange will engage within the groove 83. Also, the mandrel notch 89 will be moved upwardly away from its retaining relationship to the lock ring 91. However, the support ring notch surface 93, although having moved outwardly to some extent, will still maintain the lock ring in engaged relationship within the mandrel groove 92 to prevent separation of the setting tool mandrel and the well tool body as shown in FIGURE 3. In this position of parts, further upward setting'force can be applied sufficient to fully set the well tool.

To release the coupling mechanism 45, the setting tool mandrel 46 is lowered downwardly as shown in FIGURE 4. The engagement of the lock flange 87 within the groove 83 will prevent upward movement of the support ring 84 within the recess 81. Accordingly, the support ring 84 will move downwardly with the setting tool mandrel 46 to disengage the retaining surface 93 thereon from the lock ring 91. When the retaining surface 93 disengages, the lock ring 91 can resile outwardly to its fullest extent and into the space 95 between the support ring 84 and the upper end of the recess 81. How the lock ring 91 is completely disengaged from the well tool mandrel 16 to permit 11nrestricted relative movement between the setting tool mandrel 46 and the well tool mandrel 16.

OPERATION OF THE PREFERRED EMBODIMENT In the operation of the above-described apparatus, the setting tool 13 and attached well tool 15 are run into the well bore as shown in FIGURES l and 2 until the tool is positioned to the well at the point where it is to be set. At this point, the operator picks up on the running-in string 14 while torquing in a right-hand direction to align the J-pin 50 with the long portion of the J-slot 48. It may be readily appreciated that the direction of torquing is a function of the J-slot arrangement and such an arrangement may be provided to permit operation by torquing in either hand direction. The setting tool mandrel 46 is moved upwardly relative to the drag block assembly 48 which is frictionally held by the drag blocks 59 relative to the casing. Such upward movement of the mandrel 46 and the attached well tool 15 causes the expander cone 51 on the setting tool 13 to move upwardly relative to the slip and drag block assembly 48. The inclined surface 74 on cone 51 will engage the complimentary inner surfaces 67 on the slips 53 so as to pivot the slips outwardly into gripping engagement with the well casing. When the upwardly holding teeth on the slips 53 grip the casing, further upward movement of the expander cone 51, the setting sleeve 53 and the setting head 38 is not possible. Thereafter, upward travel of the setting tool mandrel 46 will elevate the well tool mandrel 16 relative to the setting head 38 and cause expansion of the well tool slips 34 and 26 over their respective expanders 33 and 28 as well as compression and expansion of the packing element 32. As the mandrel 16 moves upwardly, the ratchet ring 40 will ratchet downward along the mandrel teeth 44 and the ring 40 will trap the mandrel 16 in the ln'ghest position to which it is moved to lock the well tool 15 in set condition.

Preferably, the shear pin 86 is designed to rupture at a smaller magnitude of force than that required to set the well tool 15. Thus, when the pin 86 fails as shown in FIG- URE 3, the tension loading on the setting tool mandrel 46 is applied to the well tool mandrel 16 through the support ring 84 and the lock ring 91. When a suflicient upward strain has been taken on the running-in string 14 to firmly set the well tool slips and packing, the coupling mechanism 45 can be released by merely slacking off on the string 14 to move the setting tool mandrel 46 downwardly. As previously described, the support ring 84 is retained in its lower position within the recess 81 by the lock flange 87. Therefore, as the support ring 84 moves downwardly relative to the mandrel 16, the lock ring 91 can resile outwardly to its unstressed diameter into the annular space above the support ring. At this diameter, the lock ring 91 is sized to readily pass over the well tool mandrel 1'6 and will not re-engage within the groove 92.

If it is desired to apply further setting force to the well tool 15, this can be accomplished as shown in FIG- URE 4 by lowering the setting tool mandrel 46 until its lower end surface engages the setting head 38. Then the weight of the running-in string 14 can be slacked olf onto the setting head 38 to force it further downwardly along the mandrel 16. This procedure will serve to set the slips 34 and the packing element 32 even more tightly in the well bore to ensure an effective pack-off therein. In instances where the depth of the well and design of the tubing string prevent or limit the amount of tension that can safely be applied to the bridge plug for the setting operation, such use of the weight of the tubing string to further accomplish the setting operation can be a desirable feature.

Inasmuch as the coupling mechanism 45 has now been released, thereby releasing the setting tool mandrel 46 from the well tool 15, the setting tool 13 may now be released from the casing in the following manner. Upward movement of the tubing string 14 will elevate the setting tool mandrel 46 to a position placing the release snap ring 72 in contact with a lower surface of support ring 73. Further upward movement of the mandrel 46 forces the support ring 73 from beneath the expander cone 51 to permit the cone to collapse inwardly. The radial inward movement of the cone removes the supporting surface 74 from beneath the slips 63, thereby permitting the slips to pivot inwardly and out of gripping engagement with the well casing P. As the mandrel 46 continues its upward travel, the upper end of the support ring 73 will engage the lower end of the drag block and slip assembly 48 to space the slips 63 away from the cone 51. Accordingly, the setting tool 13 can be retrieved from the well bofe. The setting tool mandrel 46 has a full opening bore whereby a perforating gun or the like can be readily passed therethrough.

A new and improved mechanical setting tool has been disclosed for use in setting well tools such as bridge plugs or the like. The setting tool is operable by simple surface manipulation of the running-in string and has a desirable full open bore therethrough when released from the well tool. The setting tool includes a coupling mechanism which enables the provision of such full bore, and which is simple and foolproof in operation and extremely sturdy. Moreover, the setting tool is arranged whereby additional setting force can be applied to the well tool after the setting tool is released therefrom in a convenient manner.

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from the broader concepts of this invention and, therefore, the aim is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. Releasable coupling apparatus comprising: an inner tubular member disposed within an outer tubular member; laterally movable latch means between said members and engaging in said inner member; support means abutting said latch means and retaining said latch means in engagement in said inner member; releasable means for maintaining said support means in abutting and retaining relationship with said latch means and for coupling said support means to said outer member; recess means to permit movement of said support means away from said latch means and said latch means out of engagement with said inner member upon release of said releasable means; and means for holding said support means out of retaining relationship with said latch means upon movement of said support means away from said latch means.

2. The apparatus of claim 1 wherein said latch means is an expansible and contractible annular member.

3. The apparatus of claim 2 wherein said support means is an expansible and contractible annular member.

4 Releasable coupling apparatus comprising: an outer member; an inner member telescopically disposed within said outer member; groove means in said inner member and laterally movable latch means engaging in said groove means; elongate recess means in said outer member having a stepped surface to provide a recess enlargement; support means abutting said latch means and retaining said latch means inwardly in said groove means; releasable means for maintaining said support means in abutting and retaining relationshipwith said latch means and for coupling said support means to said outer member in one relative position; and means active upon release of said releasable means and upon movement of said support means to another realtive position and engageable with said recess enlargement to retain said support means in said other position, whereupon said support means no longer retains said latch means inwardly, thereby permitting outward'movement of said latch means for engagement in said groove means.

References Cited I FOREIGN PATENTS 730,339 5/1955 Great Britain.

DAVID i. WILLIAMOWSKY, Primary Examiner DAVE W. AROLA, Assistant Examiner US. Cl. X.R. '285 l8, 307, 321 

